In recent days, President Trump has heightened his anti-immigration rhetoric, now signaling that he will not renew the Temporary Protected Status (TPS) that shields more than 300,000 immigrants from deportation. Since 1990, TPS has provided a haven for people already residing in the United States who are fleeing or reluctant to return to 10 specific countries affected by dangerous situations, including ongoing armed conflict and environmental disaster. While TPS does not offer a path to citizenship, it does allow people to live and work in the United States until it is safe to return home.

Terminating TPS would have dire humanitarian consequences for people who have lived in the United States for years and cannot safely return to their countries of origin. Indeed, it was alarm at the humanitarian failures of existing immigration and asylum policies that spurred activists to push policymakers to create TPS. Their efforts throughout the 1980s show that sustained legislative pressure by grass-roots activists matters — an important lesson for immigrants and advocates as they challenge the rhetoric and policies coming out of the White House today.

During the 1980s, a brutal civil war in El Salvador forced several hundred thousand people to search for safety outside the country’s borders. The conflict killed 75,000 people, and thousands more were subject to torture, mutilation and rape at the hands of right-wing death squads. The war displaced more than a million people, a quarter of the small country’s population, and half of them turned to the United States for help.

These refugees undertook the perilous journey to the United States, with no guarantee of safety. While tens of thousands of Salvadorans sought political asylum, only a few secured it. That’s because the Reagan administration saw refugee admissions as an extension of foreign policy. It favored asylum seekers fleeing Communist-affiliated regimes, while denying the claims of people like the Salvadorans, who were fleeing a government supported by the United States.

The administration carefully characterized Salvadorans as “economic migrants” fleeing poverty rather than as refugees. Despite the continuing violence, the administration deported thousands of people back to El Salvador, sending a message to thousands more residing in the United States that their claims for safe haven would fall on deaf ears.

The plight of Salvadorans and others fleeing U.S.-backed regimes in Central America moved people to action. Religious communities in Arizona were among the first to stand up for Salvadorans, with churches, synagogues and Quaker meetinghouses providing sanctuary for these refugees, sheltering them from deportation. This activism came at a cost: More than a dozen sanctuary activists were indicted in 1985, and eight were convicted of breaking federal laws. But the Sanctuary Movement continued to spread beyond Arizona, amplifying the stories of Salvadorans and raising the profile of the issue throughout the country.

Far from Arizona’s Sonoran desert, in the Jamaica Plain neighborhood of Boston, a small group of concerned neighbors met to discuss what could be done to address the role the U.S. government was playing in amplifying violence in Central America, and to advocate for legal status for Salvadorans in Boston and around the country. They became the Jamaica Plain Committee on Central America (JPCOCA) and spent their Saturdays manning a table outside the post office to collect signatures on petitions. They worked with local organizations such as Centro Presente, Oficina Hispana, Citizens for Participation in Political Action and the American Friends Service Committee to gain the attention of their congressman, Joe Moakley (D-Mass.).

Moakley considered himself a “bread and butter” politician who was driven by the concerns of his constituents. Foreign affairs weren’t on his radar — he often joked that his idea of foreign affairs was to go to East Boston to get an Italian sub. But when his constituents, including JPCOCA activists and Salvadoran refugees who feared returning to El Salvador, came to him with their concerns, something remarkable happened: He listened.

Beginning in 1983, Moakley introduced legislation that would protect Salvadorans from detention and deportation. When the bill failed to become law, Moakley reintroduced it in the next Congress. And the next Congress. And again in 1989. He recognized that for many Salvadorans, this protection could literally mean the difference between life and death.

Despite Moakley’s efforts, Salvadorans in the United States continued to be denied asylum at high rates because the United States remained supportive of the regime in El Salvador. Less than 3 percent of Salvadoran and Guatemalan asylum seekers in 1984 were granted asylum, while people fleeing regimes the United States did not support succeeded at much higher rates: 60 percent of Iranians, 40 percent of Afghans and 32 percent of Poles. The Reagan administration continued to assert that Salvadorans were merely “economic migrants” in search of economic opportunities, rather than victims of political violence.

Lawyers and activists challenged this logic in the courts and in Congress. They brought a class-action suit in 1985 against the Reagan administration on behalf of Salvadoran and Guatemalan refugees, arguing that the administration’s denial of their asylum claims violated their rights. A 1991 settlement of the American Baptist Churches v. Thornburgh lawsuit eventually allowed new asylum hearings for certain applicants.

At the same time, activists pushed the administration to authorize a special immigration status called “Extended Voluntary Departure” that would allow people from certain countries to remain and work in the United States until it was safe to return. When the Reagan White House resisted, these activists continued to pressure Moakley, who, in turn, continued to tirelessly advance legislation.

In 1989, six Jesuit priests, their housekeeper and her young daughter were murdered in El Salvador, focusing U.S. attention on the war there for the first time since the murder of Archbishop Oscar Romero in 1980. Moakley headed a special congressional Task Force on the Salvadoran government’s response to the murders, bringing attention to official complicity. That same year, Moakley became chairman of the House Rules Committee, putting him in a powerful position to enact the legislation that had become his passion.

With renewed national attention and greater access to power, Moakley and the activists finally won. Congress extended Temporary Protected Status to Salvadorans as part of the Immigration Act of 1990.

In the 27 years since its passage, TPS has protected hundreds of thousands of people from designated countries from being deported, not only to countries experiencing violence from war but those affected by other forms of instability including famine, natural disasters and epidemics. Although it does not provide a path to permanent residency and citizenship, the policy remains one of the country’s most essential humanitarian protections. Ending TPS would harm communities across the country.

TPS exists because of the extraordinary and protracted efforts of immigrants and activists — and the policymaker they convinced to act. As TPS recipients and advocates push the administration to preserve and improve the lifesaving program, they would do well to remember the hard work and compassion of activists that brought it into existence in 1990 when they, too, took on a hostile and reluctant White House, and won.